KR20240054995A - suction stent - Google Patents

Abstract

The present invention relates to a stent for insertion into a hollow organ of a human or animal patient, particularly the gastrointestinal tract, for the treatment of local anastomosis insufficiency, for vacuum sealing leaks to specific anatomical regions of the hollow organ, for example the gastrointestinal tract. You can use it. Accordingly, a stent 10 is proposed for introduction into a hollow organ of the human or animal body, preferably the gastrointestinal tract, in particular the intestine, comprising an internal fluid passage 18 from one end of the body 12 to the longitudinally opposite end of the body 12. ), a radially expanding body 12 having a wall 32 demarcating it, liquid-tight covering the surfaces 34, 36 of the wall 32 along the entire circumference and along a first predefined region in the longitudinal direction of the body. A flexible first layer 20, and covering the outer surface 36 of the wall 32 along the entire perimeter and along a second predefined area in the longitudinal direction of the body 12, at least partially covering the first layer ( 20) and has an elastic and porous second layer 22. Furthermore, the first layer 20 is arranged on the surfaces 34,36 of the wall and extends at least partially through the wall 32 in the radial direction and/or the second layer 22 is mechanically attached to the body 12. is fixed.

Description

suction stent

The present invention relates to a stent for insertion into a hollow organ of a human or animal patient, particularly the gastrointestinal tract. Such stents can be used, for example, for the treatment of local anastomosis insufficiencies, in particular for vacuum sealing leaks to specific anatomical regions within hollow organs.

Leakage of gastrointestinal surgical sutures (anastomoses) is one of the most dangerous and therefore serious complications after abdominal surgery. When a leak occurs, the contents of the stomach or intestines enter the abdominal cavity, causing peritonitis, which is still fatal in about 20% of cases today. Treating these leaks depends on their exact location and the damage already caused by the leaked contents of the intestines. In the best cases, suture healing is delayed and the functional outcome (e.g., continence) of the surgery is impaired. However, much more invasive measures, such as reoperation to remove intestinal continuity and place a colostomy, are often necessary to avoid putting the patient's life at risk. The colostomy process is reversible only in very few cases.

For example, attempts to close anastomotic insufficiency using endoscopically inserted endoluminal covered stents or other conventional stents have often been shown to be unsuccessful in adequately closing the sutures within the hollow organ. This insufficiency may be due to the mismatch between the commonly applied stent and the irregularly shaped intestinal wall. Self-expandable stents with high resilience cannot be used to completely seal the leaking suture area. This may cause further damage or rupture of the suture.

Moreover, in exceptional cases, even if the defect is in fact completely sutured, the contents of the hollow organ, for example the contents of the intestines, which have entered the suturing area, cannot be drained. Therefore, the formation of abscesses in the sutures, especially in the gastrointestinal tract, occurs virtually inevitably, further worsening the local pathological and medical condition of the patient.

A porous foam material that can be placed on the exterior of the stent body and held in place by radially outward pressure exerted by the stent body to improve sealing against the wall of a hollow organ, e.g. the intestine. Implementation of was proposed. Additionally, drainage of harmful contents from each hollow organ can be achieved by providing a cannula outside the stent body, such as inside a porous material. Additionally, this may improve the seal of the suture by applying a vacuum or may even replace the need to apply sutures to close the lesion until the lesion heals.

However, with long-term use of stents, local tissue in-growth can occur, and porous materials in particular and mesh-shaped stent bodies in general have been shown to be the most vulnerable. Due to the preferably temporary nature of stent application, which promotes the healing process of the (leaking) suture, removal or deflation of the stent may result in additional difficulties in preventing damage to the surrounding tissue.

Therefore, there is a need to further improve current stents in terms of patient safety and therapeutic efficacy during and after application of the stent.

It is an object of the present invention to provide a stent that effectively seals any local defects, such as leaking surgical sutures, while also facilitating removal after long-term use. Advantageously, such stents may effectively remove fluid accumulated in defects in hollow organs of the human or animal body.

This object is achieved by the stent of the present invention according to the independent claim. Preferred embodiments are described in the dependent claims, detailed description and drawings.

Accordingly, a stent is proposed for introduction into a hollow organ of the human or animal body, preferably into the gastrointestinal tract, especially the intestine. The stent includes a radially expandable body having a wall defining an internal fluid passageway from one end of the body to a longitudinally opposite end of the body. The stent also includes a first layer that is liquid-tight and flexible and covers the surface of the wall along the entire circumference and along a first predefined region along the length of the body, and a second layer that is elastic and porous. The second layer covers the outer surface of the wall along the entire circumference and along a second predefined area along the length of the body and at least partially covers the first layer. The first layer is arranged on the wall surface and extends at least partially through the wall in the radial direction and/or the second layer is mechanically fixed to the body.

The wall may be at least partially embedded in the first layer, such that any holes or cavities present in the wall may be filled by radial extension of the first layer through the wall. Accordingly, direct contact with the wall is ensured and maintained during stent deployment, thereby improving the sealing function of the fluid passageway and the outward-facing first layer. Moreover, the radial extension through the wall not only partially increases the thickness of the first layer but also provides mechanical stability of the first layer by fixing it to the wall in the radial, longitudinal and circumferential directions.

Moreover, by protruding or penetrating through the wall, the ingrowth of local tissue is damaged. For example, the stent body may have a mesh shape, ie a wire structure, such that the radial extensions of the first layer fill the mesh shape. Therefore, local tissue essentially cannot grow or become entangled through the mesh-like structure of the stent body. This equally applies to other types of stent bodies, for example having a porous structure or a (continuous) pore pattern. Accordingly, removal of the stent is facilitated, potential tissue damage during removal can be reduced, and the mechanical or structural stability of the first layer is improved to ensure a sealing function when applying the stent.

The mechanical fixation of the second layer to the body also ensures that the stent can be safely removed and that the second layer does not remain within the patient when the stent is deflated, even if limited local tissue ingrowth occurs through the porous structure. Mechanical fixation of the second layer during application ensures proper positioning of the second layer so that the seal is improved against the inner wall of the hollow organ at the site of the lesion or suture and is maintained even during movement or contraction of the surrounding tissue.

Accordingly, both the configuration of the first layer extending radially through the wall and the anchoring of the second layer to the stent body achieve effective sealing of the local tissue defect and facilitate removal of the stent after prolonged use. These features can be used as alternative technical solutions, but synergistically improve the safety of the stent during application and removal, so that the stent according to the invention can comprise an alternative, preferably an advantageous configuration of the first layer and of the second layer. It can include all advantageous configurations.

The body or fluid passageway of the stent body (similarly referred to throughout the invention) may be understood as a through channel or internal cavity with opposing openings. Accordingly, the body forms a longitudinally open hollow body with a lumen, through which fluid can enter the passageway through one end and exit the passageway through the opposite end. Preferably, the body is essentially cylindrical or tubular, but may also include other cross-sectional shapes, such as an oval shape, for at least one or more regions of the body. Preferably, the body is an elongated body with an essentially continuous longitudinal extension, but one or more curvatures may be present, which may allow, for example, to adapt the stent to the specific anatomy corresponding to the respective application.

Preferably, the radially expandable body has a mesh shape that facilitates expansion and compression of the stent and provides adaptability to the anatomy of the application area, eg the intestinal wall. The body may be formed of a shape memory alloy, such as nitinol, which further facilitates folding the stent for delivery to the target lesion or suture via the delivery system and catheter. Additionally, the body can be constructed to be self-expandable, which can be facilitated using such shape memory alloys or other metals. Additionally, these materials provide elasticity of the body, providing adaptability to the local anatomy of the application site and, depending on the size of the stent body, such that the stent is held in place by radial and/or longitudinal forces. do. Shape memory alloys may be preferred for structural stability, but alternatively the stent body may be formed from a self-expandable plastic material.

The luminal diameter of the stent according to the invention, i.e. the radially expandable body, is preferably about 10 mm to 50 mm, preferably about 15 mm to 35 mm, especially about 15 mm to 30 mm, most particularly preferably about 28 mm (e.g. in the colon region). (e.g., when used in the esophagus) or about 21 mm (e.g., when used in the esophagus). In any case, the diameter of the stent is selected depending on the area of application so that the passage of the substance of interest (e.g., food in the case of the intestinal tract) through the respective hollow organ is unimpeded. The dimensions may apply to the entire inflatable body, but at least one of the opposite ends or end regions may have a greater radial extension, or the dimensions may be met by opposite ends or end portions between the opposite ends. The portion of can be smaller in size.

Additionally, the liquid-tight and flexible first layer may be elastic and/or compressible or foldable, such that the integrity of the material of the first layer is not adversely affected in the folded state, and preferably the material expands the first layer in an essentially homogeneous manner. facilitates expansion, and preferably also promotes expansion or at least does not impair expansion of the main body. The liquid-tight first layer prevents liquid outside the stent body from entering the fluid passageway and vice versa, thereby preventing fluid in the hollow organ from inadvertently invading surrounding organs or entering the blood circulation system.

Preferably, the first layer is oil-tight or air-tight. If the stent is equipped with an evacuation means such as a cannula and placed outside the first layer, this allows a vacuum to be applied between the first layer and the inner wall of the hollow organ. Therefore, any contents leaking into this intermediate space can be effectively expelled through negative or suction pressure and a (small) vacuum can further promote sealing of the lesion or suture, thus hastening the healing process.

The first layer may be formed of or comprise a plastic or polymer material, and is preferably selected from the group comprising polyurethane, latex and silicone. Preferably, the first layer is silicone-based.

Preferably, the elastic and porous second layer is moldable and/or compressible without compression forces returning it to its original uncompressed state. The second layer may surround the stent body and, for example, may be tubular with a central through hole receiving the stent body and the first layer. The second layer can be formed from a closed pore material, i.e. in the form of a foam, or an open pore material, i.e. in the form of a sponge. Preferred materials for this purpose are, for example, plastic material foams comprising or consisting of polyurethane, polyvinyl alcohol or mixtures of such plastic materials.

Preferably the second layer comprises a thickness of about 5 mm to about 20 mm, preferably about 5 mm to about 10 mm, the exact dimensions being dependent on the anatomical dimensions of the application site and physical requirements taking into account, for example, the required elasticity, and the stent body. It is determined by the necessary connection between the and the inner walls of the hollow organ.

Preferably, the overall configuration of the stent according to the invention is fully expandable, especially in organs such as the gastrointestinal tract, preferably the esophagus, small intestine, mainly the rectum, sigma, colon descendens or colon transversum. It can be applied through traditional application methods at application locations within the body.

The first layer may be disposed on an inner wall surface or an outer wall surface and may extend radially to at least fill the space between said surfaces for embedding and mechanically securing the stent body to the first layer. Preferably, the first layer is disposed at least on the outer wall surface of the stent body. More preferably, the first layer covers the inner and outer surfaces of the wall. Thereby, the stent body, ie the walls of the stent body, are completely embedded by the first layer. In contrast to implementations using liquid-tight foils, this configuration provides a thicker layer of material, effectively reducing leakage and non-uniformity, and preferably ensuring that the first layer is fully secured to the stent body, which may be mesh-shaped. Moreover, such embedded configurations and corresponding structural connections can prevent folding of the first layer, providing a more homogeneous external profile and reducing the potential occurrence of wear during application.

Preferably, the first predefined region and/or the second predefined region correspond to a region of the body with an essentially continuous cross-sectional area. This essentially continuous cross-sectional area may be provided over the entire area between the opposing ends and may be, for example, tubular, circular or elliptical in shape. However, intermediate contractions may be present, for example to ensure mechanical stability or to adapt to the anatomy. Cross-sectional areas may relate to walls, passages, or both. Matching each predefined area to a continuous cross-sectional area facilitates manufacturing and can also prevent each layer from swelling, folding, or wrinkling during expansion and/or application of the stent.

Accordingly, the first predefined area and the second predefined area may essentially correspond to each other. Alternatively, the first layer may also extend longitudinally beyond the second layer at each tip or tip region of the stent body. For example, a stent may include drainage means in the form of a cannula that is received along the stent body but can be guided through the stent body at each distal region. To ensure that the fluid passageway of the stent body is liquid-tight at each such distal region while the discharge means extend through the corresponding wall, a first layer may not be applied to the distal region and may be of a liquid-tight configuration at the distal region. Other means for maintenance may be provided. As will be explained in detail below, for example a liquid-tight, preferably oil-tight foil may be provided in said end region of the inner wall surface and continuous with the first layer, and the discharge means or cannula may be provided on the exterior and at least partially of the foil. is placed between the wall and the foil within the end zone.

The first predefined region and/or the second predefined region may be longitudinally delimited by at least one end region of the body, the at least one end region having an enlarged radial extension.

At least one, preferably both, of the tip regions may have, for example, a variable cross-sectional area or shape and/or may exhibit a radial increase immediately adjacent to a region of the stent body having an essentially continuous cross-sectional area. . If one of the distal regions is configured to receive a discharge means or a cannula, the first layer may be delimited by said distal region and a foil, for example a tubular foil, may instead be placed inside, as described above. Can be placed on the wall surface. Preferably, these foils are oil-tight, i.e. airtight and water-proof, and may be formed, for example, of polyurethane, latex and/or silicone or silicone-based materials. The foil can be fixed to the first layer by a sealant, especially a hydrogel, such as silicone, hydrocolloid or lyogel, to form a homogeneous and structurally stable sealing structure.

The second layer may at least partially cover each end region, as long as the overall radial extension of the second layer is essentially constant. For example, if the tip region has progressively increasing radial extension, the thickness of the second layer may be reduced accordingly until it reaches zero. This provides a smoother transition between the (outer) second layer and the radially protruding tip region.

Each end region may have a mushroom shape, dome shape, toroid shape, donut shape, etc. in the longitudinal cross-section of the body. Accordingly, the entire body may have a barbell shape.

The specific shape includes rounded surfaces without sharp edges and reduces the risk of damaging surrounding tissue, for example during deployment or dislodgement of the stent body. Moreover, the rounded shape provides improved fitting to the local anatomy of the application site. That is, it better adapts to the inner wall of the hollow organ while exhibiting elasticity that holds the stent firmly in place at the application site.

In this regard, the enlarged radial extension of both opposing apical regions also allows the stent to be placed such that a lesion or suture is located between the respective apical regions, allowing targeted application of vacuum or evacuation of these specific locations. It can be facilitated or improved.

Additionally, both the first predefined area and the second predefined area may be delimited by both opposing end areas. Accordingly, the first predefined region and the second predefined region may comprise essentially the same longitudinal extension. However, as described above, the second layer may at least partially cover each end region as long as its thickness is reduced. Additionally, each end region can be configured to receive and receive discharge means, and instead of the first layer a liquid-tight foil can be implemented inside the fluid passageway or under or on the inner wall surface. However, the opposite end region which does not receive such discharge means may optionally be at least partially covered and embedded with the first layer.

Delimitation of the second layer by both opposing end regions may also provide that the second layer is mechanically secured in a form-fitting manner by the longitudinally opposing end regions. Depending on the dimensions and type of material for the second layer, a loose form fit can be provided so that, for example, radial or longitudinal forces applied to the second layer can still result in corresponding displacements. However, delimiting provides that the second layer is biased between opposing end regions to ensure proper coverage of the stent to the target site, at least during stent deployment.

Depending on the dimensions and materials used for the second layer, the second layer may be secured to the stent body (or first layer) to some extent by a friction fit or a press fit, for example in a rotational and/or longitudinal direction. .

To improve the fixation of the second layer to the stent body, the second layer can also be mechanically attached to the body by at least one thread, the thread being at least one thread on the outer surface of the second layer. A first thread portion disposed in the second layer to provide an eyelet and a second thread connecting the at least one eyelet to each connection point in an adjacent end region of the body not covered by the second layer. Includes part.

Preferably, adjacent end areas are not covered by the first layer, for example when receiving and receiving the discharge means. This may facilitate connecting the second threaded portion to the respective end region, which is preferably the proximal and/or nearest end region. To improve the structural stability of the second layer, preferably at least one eyelet is spaced longitudinally from the end surface of the second layer corresponding to each end region. Preferably, the at least one eyelet may be positioned between about 5 mm and about 20 mm, preferably between 8 mm and 15 mm or about 10 mm from each end surface.

The thread may be formed from a biocompatible but non-biodegradable material, such as a suture material. Preferably, the thread is formed of polyethylene (PE), polypropylene (PP) or polytetrafluoroethylene (PTFE). Connections to the connection points may be provided by individual knots at the connection points, for example on intersecting struts of the mesh-like body, or by loops to provide laced fastening. It can be provided through Through the connection, the second layer is fixed in both the radial and longitudinal directions.

Preferably, at least two eyelets are provided by the first thread portion, the eyelets being circumferentially spaced apart. In this way, the potential movement of parts of the second layer, ie in the longitudinal and/or radial directions, can be reduced. The second threaded portion may connect each eyelet individually to each connection point, or may connect the eyelets to each other via one or more connection points, for example using corresponding loop and lace techniques.

Preferably, the eyelets are equally spaced along the circumference and/or between three and six or four eyelets provided by the first thread portion. The same spacing and plurality of eyelets can reduce the stress acting on the second layer and effectively prevent shrinkage due to mechanical attachment. For example, by providing four eyelets displaced about 90° along the circumferential direction, the second layer can be pulled towards the stent body in such a way that the mechanical attachment is not too difficult and the second layer is evenly distributed. However, depending on the requirements of the stent and the composition of the second layer used, additional eyelets may be provided.

A variety of connection methods may be provided, and loops and/or knots may be used for multiple connection points and eyelets. Preferably, the second thread portions alternate between adjacent connection points and eyelets, and/or each connection point is connected to two adjacent neighboring eyelets by the second thread portion.

Accordingly, each eyelet can also be connected to two adjacent connection points. The alternating pattern should be understood essentially as a zigzag pattern between, for example, circumferential lines formed by connection points and circumferential lines formed by eyelets. Each connection may be formed by a knot or loop, for example by tying the second threaded portion through the eyelet and guiding the second threaded portion, for example, around the connection point. If the connection point is formed by the intersection of connecting struts in the form of a wire mesh of the stent body, the second threaded portion can be guided from each eyelet around an adjacent strut or from the intersection of struts in the tip area and further towards a more adjacent eyelet. It can be guided, forming a loop between the eyelets through the connection point. Additionally, the connection points may be specifically formed on the outer surface of the stent body for this purpose, for example round projections having or delimiting retaining elements, kerfs or slits, or corresponding eyelets. It can be formed in the form of.

As mentioned above, the tip region may also have a greater radial extension, for example, may be mushroom shaped and extend radially beyond the tubular region of the stent body having an essentially continuous cross-sectional area. In such a configuration, this may facilitate connection as it reduces the risk of shrinking the second layer (and potentially the stent body and/or first layer) and makes the connection point more accessible. Preferably, the connection points are selected or arranged to minimize radial extension of the second thread portion, although radial extension may be advantageous. This facilitates stent placement and function and reduces potential adverse effects on surrounding tissue structures while implanted.

To further improve force distribution and provide more uniform and homogeneous attachment of the second layer to the stent body, each connection point can be arranged essentially equidistant to two adjacent neighboring eyelets. Therefore, preferably the connection points are equally spaced along the circumference of the stent body and are arranged essentially centrally between two adjacent neighboring eyelets, but offset longitudinally. The equidistant arrangement of the connection points prevents individual eyelets (and thus the second layer) from being biased toward a particular connection point.

Between adjacent eyelets the first thread portion may be arranged in the second layer of material. Accordingly, the first threaded portion can be guided through the second layer and embedded therein, so that only the eyelet formed by the first threaded portion can protrude out of the second layer. This configuration allows the larger first threaded portion between the eyelets to be retained within the second layer, suitable for both the collapsed, compressed and expanded states of the stent, for example, the anatomy of the application site or other elements of the stent. The advantage is that it does not inadvertently form loops, bends or other folds that may compromise the proper expansion and function of the stent by potentially interacting with the components. Additionally, the internal first threaded portion may reduce the amount of threaded portion in contact with surrounding tissue, thereby reducing friction or incision toward the tissue. Additionally, the potential for tissue invasion or ingrowth around the first thread portion is also reduced.

The first thread portion and the second thread portion may be formed of separate threads, but it is preferable that the first thread portion and the second thread portion be formed of a single thread. In other words, the first threaded portion may be disposed on and/or within the second layer to provide each one or more eyelets and be continuous with the second threaded portion, which connects the eyelet(s) to each connection point. Connect to (s). For example, a first thread portion may be guided through the second layer, with the leading end only protruding out of the second layer to form each eyelet, for example by forming an outer loop, and the trailing end The lagging end forms a first eyelet by one or more ties connected to the first slab portion at the trailing end. After the last eyelet, the leading edge of the first threaded portion continues into the second threaded portion, connecting each eyelet via one or more connection points, for example in an alternating zigzag pattern.

By using one and the same thread, i.e. a single piece of thread, fewer knots may be required, which may reduce the incidence of biasing of the second layer and/or stent body and provide physiological stability since fewer knots are present. This may be scientifically advantageous and provides a smoother outer surface of the stent. Moreover, the use of a single thread may be beneficial to the overall structural stability of the thread.

Attachment of the second layer may be provided at both distal regions of the stent body, but preferably the adjacent distal regions are configured to receive the cannula. Accordingly, the adjacent distal region may correspond to the proximal distal region of the stent. This is particularly true because frictional and/or tensile forces arise at this end and thus attach the second layer directly to this end, thereby reducing the potential leverage or longitudinal movement or folding of the second layer towards the distal end for stent removal and retraction. It is especially advantageous when

Accordingly, the stent may further include a cannula disposed between the second layer and the first layer and housed essentially outside the body. The cannula or ejection means may generally be connected to the second layer and/or the stent body to ensure proper positioning of the cannula within the stent, ie between opposing ends or end regions. The cannula may be connected to a vacuum or negative pressure source, for example, to provide a vacuum between the first layer and the inner wall of the hollow organ when implanted and deployed. However, optionally, preferably additionally, for example, using a cannula, saline or other biologically compatible fluid, or a liquid or gel-like tissue sealant to promote healing of lesions or leaking sutures. Other functions can be additionally provided by rinsing or flushing the application area, such as applying .

The cannula may be received through the distal region having a radial extension greater than the fluid passageway, to minimize the radial dimensions of the stent and passageway. For example, the distal region may be mushroom-shaped or dome-shaped, with the cannula being introduced through a passageway and extending through the walls of the distal region to be received and received along the exterior of the stent body between the distal regions.

According to another aspect of the invention, a delivery system for delivering and deploying a stent in a target anatomical region is proposed, comprising a catheter carrying a stent according to the invention in a compressed state. Preferably, the delivery system is configured and dimensioned to enable movement and delivery of the stent to the site of application within the patient's gastrointestinal tract, preferably the esophagus, intestine, primarily the rectum, sigma, descending or transverse colon.

Preferably, the catheter comprises a distal end cap made of a flexible material, the distal end cap defining an internal cavity and having a longitudinally convex, rounded end surface. The end surface has at least three, preferably four, equally spaced slits in the circumferential direction from the outer surface towards the inner cavity.

Thereby, a small opening for the guide wire can be formed and the diameter of the corresponding moving or distal bead can be reduced, which is advantageous for the patient in terms of the preferred minimally invasive method. A corresponding number of flaps are formed on the end surface by slits, which due to the flexible material can be biased in an open position or in radially and longitudinally outward positions to provide a continuous through hole for the compressed and/or folded stent. there is. In this regard, the four-slit configuration provides much more flexibility and reduces disruptive forces on placement and guidance of the stent out of the catheter.

For example, compared to a single slit configuration that requires a larger slit and end surface by providing a limited opening of the end surface facing the internal cavity, an end cap with three or more slits can be of smaller dimensions. This also applies compared to pivotable configurations, which require larger dimensions since the closure of the end cap must open beyond the radial extension of the actual opening.

Compared to these configurations, the end cap according to the invention also significantly facilitates the manipulation of the delivery system, since the slit easily responds to the advancement of the stent out of the catheter and no further actuation is required.

Each shape of the end surface defined by two circumferentially adjacent slits can also be cut at the free end. That is, as described above, the slits can partition the flaps, and the flaps can be separated only by the slits and arranged adjacent to each other in the circumferential direction. These flaps, which may have an essentially triangular shape, are attached only to one end surface of the flap and its free end is placed at the intersection of the slits. There is a junction where the flap ends can be cut or rounded to provide a (small) opening towards the internal cavity. This further promotes the advancement of the catheter and further reduces friction at the free end. Accordingly, a more positive bias towards the open position as well as a more positive closure of the end cap towards the internal cavity can be achieved.

The present disclosure will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings:
Figure 1 shows a longitudinal cross-sectional schematic diagram of a stent according to the invention.
Figure 2 shows a schematic, reduced view of the stent according to Figure 1 from the distal end region to the proximal end region.
Figure 3 is an enlarged view of the wall of the stent body with a first layer configuration.
Figure 4 is an enlarged view of the wall of a stent body with an alternative first layer configuration.
Figure 5 is an enlarged view of the wall of the stent body with the first layer configuration according to Figure 1;
Figure 6 shows a schematic longitudinal end section of a catheter with an end cap at the distal end.
Figure 7 shows the embodiment according to Figure 6 viewed longitudinally at the distal end.

Hereinafter, the present invention will be explained in more detail with reference to the attached drawings. In the drawings, identical components are given the same reference numerals, and overlapping descriptions may be omitted to avoid duplication.

Figure 1 shows a schematic diagram of the stent 10 according to the present invention in longitudinal section. The stent 10 is fully expandable and is configured to be deployed by conventional application means into a hollow organ, in particular the gastrointestinal tract, preferably at the site of application within the esophagus, intestines, primarily the rectum, sigma, descending or transverse colon. The stent 10 includes a body 12, which according to a non-limiting embodiment is formed of a shape memory alloy, preferably nitinol, and has an essentially continuous wire mesh shape (a variety of shapes of the stent 10). To improve understanding of the features, (not shown in Figure 1) is included. Accordingly, the body 12 is formed of an elastic, compressible, collapsible material and is self-expandable, although other configurations that allow for mechanical expansion may also be provided.

Body 12 has an essentially tubular shape and includes an essentially continuous cross-sectional area for the largest portion of body 12 and extends longitudinally from the proximal end 14 towards the distal end 16. The terms 'proximal' and 'distal' are understood as closest to the insertion site and closest to the application site, respectively, during the surgical procedure for delivery of the stent 10 towards the application site. The continuous cross-sectional area is limited by a proximal end region 14 and a distal end region 16, which comprise various diameters and radial extensions, with the largest portion having a radial extension that exceeds the radial extension of the continuous cross-sectional area. The larger radial extension facilitates securing the stent 10 during placement within the hollow organ and may also provide, for example, for a lesion or suture to be arranged between the proximal end 14 and the distal end 16. there is. Thereby, the lesion or suture can be effectively separated. The proximal end 14 and the distal end 16 both have circular or convex surfaces and have sufficient radial extension to allow the stent 10 to be properly secured in place, providing a degree of adaptability to the surrounding tissue at the site of application. It has a toroidal or mushroom shape.

The body 12 or its walls from the proximal end 14 to the distal end 16 also form a continuous fluid passageway 18. The passageway 18 is sealed by the first layer 20 towards the inner wall of the hollow organ at the site of application. The first layer is liquid-tight and may be formed, for example, from a silicon-based material. The first layer 20 ensures that separated lesions or leaking sutures are no longer susceptible to contamination with the contents of hollow organs, e.g. intestines, and vice versa, effectively preventing potential high-risk medical complications. there is. The sealing towards the inner wall of the hollow organ is also facilitated by a second layer 22 surrounding the first layer 20 and comprising a biocompatible foam or sponge to provide sufficient moldability and conformability to local tissues and anatomy. It can be formed from any material. Accordingly, these materials may also assist in mechanically securing the stent 10 to the desired application site. Preferably, a continuous cross-sectional area demarcates a first predefined area of the first layer (20) and a second predefined area of the second layer (22).

By means of the improved sealing provided by the first layer 20 and the second layer 22 as well as the passageway 18 and the end regions 14, 16, the normal functioning of the hollow organ can be established while e.g. For example, healing of lesions such as anastomoses or leaking sutures is accelerated.

In this embodiment, the body 12 or a region of the body 12 with a continuous cross-sectional area is completely embedded in the first layer 20. The mesh-like structure of body 12 extends from one side of a wall of body 12 to the opposite side of said wall, for example from an inner wall to an outer wall, as explained in more detail below in connection with FIGS. 3 to 5 . Allows the material of the first layer to extend radially up to the surface. By the embedded configuration, the first layer 20 is mechanically fixed to the body 12 and the structural stability of the first layer 20 can be improved. Accordingly, proper function of the stent 10 and liquid-tight isolation of the lesion or suture can be ensured even after prolonged application times or placement in complex tissue structures. Additionally, the embedding allows tissue ingrowth towards or around the mesh-like body 12 to be effectively prevented or at least reduced.

Proper positioning and functioning of the second layer 22 is further ensured by a plurality of eyelets 24 formed by corresponding first thread portions and arranged equally spaced along the outer periphery of the second layer 22 . For example, the eyelet 24 may be made of a sealing material such as PP, PE, or PTFE, or may be formed of a braided material. Additionally, each eyelet 24 is connected to the body 12 via a respective connection point 26 using a second threaded portion 28, preferably comprising a first threaded portion 24 and a second threaded portion 24. Portion 28 is formed from a single continuous thread. The connection points 26 are arranged in the proximal end region 14 , preferably at each point having a radial extension greater than that of the eyelet 24 .

Mechanical fixation ensures that the second layer 22 can be safely removed along with the other components of the stent 10 when application is terminated, and that potential tissue growth may cause the second layer 22 to adhere to the hollow organ. Prevents the possibility of remaining Moreover, mechanical fixation facilitates proper positioning of the second layer 22 during deployment of the stent 10.

1 also shows a cannula ( 30) is shown. The proximal end 14 is not provided with the first layer 20 or the second layer 22 to facilitate introduction of the cannula 30 and fabrication of the entire stent 10. However, in this region a liquid-tight foil (not shown) may be connected to the first layer 20 and may have a tubular or conical shape, for example, to ensure proper sealing in this region as well, so that the annular proximal end region ( 14) can cover the entire (inner) circumference.

Figure 2 shows an embodiment in which second thread portions 28 are alternately arranged between eyelets 24 and connection points 26 to form a zigzag pattern. In the figure, the different levels are reduced for simplicity (the first layer 20 and the stent body 10 are not explicitly shown for improved overview), but the connection points 26 are positioned in a gradually increasing radial direction. It should be understood as arranged in the curvature of the proximal end region 14 with extension. Moreover, the body 12 is preferably formed as a mesh-like body 12, so that the connection points 26 can be formed by intersecting wires or struts, and the second threaded portion 28 is knotted or It is tied, guided or laced at the intersection, forming a loop between two adjacent eyelets 24 around the intersection.

In this embodiment, four eyelets 24 are provided, the eyelets 24 being equally spaced along the circumference of the second layer 22 . The eyelets 24 may be formed as protruding loops of corresponding first thread portions 24 arranged in the second layer 22 . Connection points 26 are also equally spaced along the corresponding circumference of body 12 in the proximal end region 14, each connection point 26 being between two adjacent and neighboring eyelets 24. It's in the middle, but offset vertically. This embodiment provides a uniform distribution of force and even mechanical fixation without providing shrinkage of the second layer 22 or the body 12, but different connection patterns depending on the requirements of the stent 10 and the area of application. It will be appreciated that eyelet 24 and/or connection point 26 configurations may be provided.

3-5 show alternative configurations of the first layer 20 relative to the wall 32 of the body 12. Accordingly, the wall comprises an inner wall surface 34 and an outer wall surface 36 relative to the passageway 18 and a plurality of (continuous) surfaces, which may be formed, for example, by a mesh-like configuration of the body 12. ) is provided with an opening (38).

In all embodiments, body 12 or wall 32 of body 12 is anchored by first layer 20 . According to the embodiment of FIG. 3 , the material of the first layer 20 is mainly arranged on the outer wall surface 36 but protrudes into the opening 38 so that the first layer 20 is mechanically attached to the wall 32. However, the passageway 18 may be essentially free of any first layer 20. Accordingly, even if the first layer 20 becomes (partially) loose, the diameter of the passageway 18 is not affected by the first layer 20 and obstruction of the passageway 18 is essentially prevented.

An alternative configuration is shown in Figure 4. The material of the first layer 20 is mainly arranged on the inner wall surface 34. This makes it possible for the radial extension of the second layer 22 to be increased, for example, or to be advantageous when a liquid-tight foil is implemented in the proximal end region 14 .

Figure 5 shows a configuration in which the entire wall 32, i.e. the outer wall surface 36 and the inner wall surface 34, are embedded by the material of the first layer 20, which also corresponds to the embodiment according to Figure 1 It is schematically shown.

6 schematically shows in longitudinal section the distal section of the catheter 40 with the end cap 42 at the distal end. Catheter 40 and end cap 42 may be part of a delivery system for delivering and deploying stent 10 to a target anatomical site, such that stent 10 (not shown) is delivered and moved toward the application site. It is maintained in the catheter 40 in a compressed and preferably collapsed state.

The end cap 42 is formed of a flexible, preferably elastic or elastic material and defines an internal cavity 46 for receiving a portion of the catheter 40 during deployment of the stent 10. Accordingly, internal cavity 46 ensures that catheter 40 can be advanced through end cap 42 when catheter 40 is in the proper position. Advancement of the catheter 40 out of the end cap 42 is also facilitated by an outwardly convex surface 44 at the distal end of the end cap 42, which is shown in more detail in FIG. As such, it includes a plurality of slits 48, preferably four slits 48.

Accordingly, the four slits 48 of the end cap 42 may be equally spaced in the circumferential direction to essentially form a cross shape, with the slits intersecting or interfacing with each other at the radial center point of the end cap 42. The slits 48 form four identically shaped flaps 50 in the shape of a triangle, which are connected only on one side of the shape and have a free end at the intersection of the flaps 50 . At the intersection, the flap 50 comprises a cut area and can be rounded to provide a (small) opening towards the internal cavity 46 . Thereby, adequate bias can be promoted during closure and opening of the end cap 42 and initial entry of the catheter 40 through and out of the end cap 42 can be supported by the small opening. And, the initial resistance of the flap 50 can be reduced due to the elasticity of the material.

The convex shape and provision of multiple slits facilitate movement and deployment of the stent 10 and also allow the use of smaller beads at the distal end of the guide wire. Moreover, the end cap 42 can be set to smaller dimensions compared to conventional solutions so that the surrounding tissue at the application site is not adversely affected by the end cap 42 and its dimensions can be fully adapted to those of the stent 10. there is.

It will be apparent to those skilled in the art that these examples and details merely describe examples of a plurality of possibilities. Accordingly, the embodiments shown herein should not be construed as limiting these features and configurations. Any possible combination and configuration of the described features may be selected according to the scope of the invention.

10... stent 12... body
14...proximal region 16...distal region
18...Aisle 20...1st floor
22...second layer 24...eyelet or first thread portion
26...connection point 28...second thread part
30...cannula 32...wall
34...internal wall surface 36...external wall surface
38...opening 40...catheter
42...end cap 44...convex surface
46...internal cavity 48...slit
50...flap 52...cut section

Claims (19)

A stent (10) for introduction into a hollow organ of the human or animal body, preferably the gastrointestinal tract, in particular the intestine,
- a radially inflatable body (12) with a wall (32) defining an internal fluid passageway (18) from one end of the body (12) to the longitudinally opposite end of the body (12),
- a first layer (20), liquid-tight and flexible, covering the surfaces (34,36) of the wall (32) along the entire circumference and along a first predefined area in the longitudinal direction of the body (12), and
- covering the outer surface 36 of the wall 32 along the entire circumference and along a second predefined area in the longitudinal direction of the body 12 and at least partially covering the first layer 20, having a second layer (22) that is elastic and porous,
The first layer (20) is disposed on the surface (34, 36) of the wall and extends at least partially radially through the wall (32), and/or
The stent, wherein the second layer (22) is mechanically secured to the body (12). In claim 1,
The stent, wherein the first layer (20) covers the inner surface (34) and the outer surface (36) of the wall (32). In claim 1 or claim 2,
The stent, wherein the first predefined region and/or the second predefined region corresponds to a region of the body (12) having an essentially continuous cross-sectional area. In any one of claims 1 to 3,
The first predefined area and/or the second predefined area is longitudinally defined by at least one end area (14, 16) of the body (12), and is defined by at least one end area (14, 16). 16) is a stent with an enlarged radial extension. In claim 4,
At least one end region in the longitudinal cross-section of the body 12 has a mushroom shape, dome shape, toroid shape or donut shape, and/or
The main body 12 is a stent having a barbell shape. In claim 4 or claim 5,
The stent, wherein both the first predefined region and the second predefined region are bounded by both opposing distal regions (14,16). In claim 6,
The stent, wherein the second layer (22) is mechanically fixed in a shape-fitting manner by longitudinally opposing end regions (14,16). In any one of claims 1 to 7,
The second layer (22) is mechanically attached to the body (12) by at least one thread,
The at least one thread is,
a first threaded portion (24) disposed within the second layer (22) to provide at least one eyelet (24) on the outer surface of the second layer (22); and
a second layer connecting said at least one eyelet (24) to respective connection points (26) at adjacent end regions (14, 16) of said body (12) not covered by said second layer (22). A stent comprising a threaded portion (28). In claim 8,
A stent, wherein the first thread portion (24) is provided with at least two eyelets (24), the eyelets (24) being circumferentially spaced apart. In claim 9,
The stent, wherein the eyelets (24) are equally spaced along the circumference and/or between three and six or four eyelets (24) are provided by the first thread portion (24). In claim 9 or claim 10,
The second threaded portions 28 alternate between adjacent connection points 26 and the eyelets 24 are adjacent to each other and/or each connecting point 26 is connected to the second threaded portion 28. connected to two adjacent neighboring eyelets (24) by a stent. In any one of claims 9 to 11,
A stent, wherein each connection point (26) is arranged essentially equidistant to two adjacent neighboring eyelets (24). In any one of claims 8 to 12,
The stent, wherein the first threaded portion (24) is arranged within the material of the second layer (22) between adjacent eyelets (24). In any one of claims 8 to 13,
The stent, wherein the first threaded portion (24) and the second threaded portion (28) are formed of a single thread. In any one of claims 8 to 14,
The stent, wherein adjacent distal regions (14, 16) are configured to receive a cannula (30). In any one of claims 1 to 15,
The stent further comprising a cannula (30) arranged between the second layer (22) and the first layer (20) and received essentially external to the body (12). A delivery system for delivering and deploying a stent (10) to a target anatomical region, comprising:
A delivery system comprising a catheter (40) with a stent (10) according to any one of claims 1 to 16. In claim 17,
The catheter (40) includes a distal end cap (42) made of a flexible material, the distal end cap (42) defining an internal cavity (46) and having a longitudinally convex rounded end surface (44), Delivery system, wherein the surface has at least three, preferably four, equally spaced slits (48) in the circumferential direction from the outer surface towards the inner cavity (46). In claim 18,
Delivery system, the shape of the end surface of which is defined by two circumferentially adjacent slits (48) truncated at the free end.